<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar class="page-nav-bar" left-arrow title="黑马头条">
    </van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div v-if="isLoading" class="loading-wrap"></div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div v-else-if="article.title" class="article-detail">
        <!-- 文章标题 -->
        <h1 class="article-title">{{ article.title }}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo"
          />
          <div slot="title" class="user-name">{{ article.aut_name }}</div>
          <div slot="label" class="publish-date">
            {{ article.pubdate | relativeTime }}
          </div>

          <!--
            <follow-user
            class="follow-btn"
            :value="article.is_followed"
            @input="article.is_followed = $event"
            :user-id="article.aut_id"
          ></follow-user>
          -->

          <follow-user
            class="follow-btn"
            :user-id="article.aut_id"
            v-model="article.is_followed"
          />
        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div
          class="article-content markdown-body"
          v-html="article.content"
          ref="article-content"
        ></div>
        <van-divider>正文结束</van-divider>

        <!-- 文章评论列表 -->
        <comment-list
          :source="article.art_id"
          @onload-success="totalCommentCount = $event.total_count"
          @post-success="onPostSuccess"
          :list="commentList"
          @reply-click="onReplyClick"
        />

        <!-- 底部区域 -->
        <div class="article-bottom">
          <van-button
            class="comment-btn"
            type="default"
            round
            size="small"
            @click="isPostShow = true"
            >写评论</van-button
          >
          <van-icon name="comment-o" :badge="totalCommentCount" color="#777" />
          <collect-article
            class="btn-item"
            v-model="article.is_collected"
            :article-id="article.art_id"
          />
          <like-article
            class="btn-item"
            v-model="article.attitude"
            :article-id="article.art_id"
          />
          <van-icon name="share" color="#777777"></van-icon>
        </div>
        <!-- /底部区域 -->

        <!-- 发布评论 -->
        <van-popup v-model="isPostShow" position="bottom">
          <comment-post :target="article.art_id" />
        </van-popup>
        <!-- /发布评论 -->
      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div v-else-if="errStatus === 404" class="error-wrap">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div v-else class="error-wrap">
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button @click="loadArticle" class="retry-btn">点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>

    <!-- 评论回复 -->
    <van-popup v-model="isReplyShow" position="bottom" style="height: 100%">
      <comment-reply
        v-if="isReplyShow"
        :comment="currentComment"
        @close="isReplyShow = false"
      />
    </van-popup>
    <!-- /评论回复 -->
  </div>
</template>
<script>
// 获取数据
import { getArticleById } from "@/api/article.js";

// 图片预览
import { ImagePreview } from "vant";

// 封装关注按钮
import FollowUser from "@/components/follw-user";

// 收藏
import CollectArticle from "@/components/collect-article";

// 点赞
import LikeArticle from "@/components/like-article";

// 文章评论
import CommentList from "./components/comment-list";

// 文章发布评论
import CommentPost from "./components/comment-post";

// 封装的回复评论的组件
import CommentReply from "./components/comment-reply";

export default {
  name: "ArticleIndex",
  components: {
    FollowUser,
    CollectArticle,
    LikeArticle,
    CommentList,
    CommentPost,
    CommentReply,
  },
  // 这个是选项，与data，props同级，给所有后代组件提供数据，后代组件可以通过inject接受
  provide: function() {
    return {
      articleId: this.articleId,
    };
  },
  props: {
    articleId: {
      type: [Number, String, Object],
      required: true,
    },
  },
  data() {
    return {
      // 文章详情
      article: {},
      isLoading: true, // 文章加载状态
      errStatus: "", // 请求异常状态
      followLoading: false, // 点击关注的loading请求
      totalCommentCount: 0, // 默认评论总数
      isPostShow: false, // 控制发布评论的显示状态
      commentList: [], //
      isReplyShow: false, // 回复评论弹出框
      currentComment: {}, // 当前点击回复的评论项
    };
  },
  computed: {},
  watch: {},
  created() {
    this.loadArticle();
  },
  mounted() {},
  methods: {
    async loadArticle() {
      this.isLoading = true;
      try {
        // 随机错误
        if (Math.random() > 0.5) {
          return JSON.parse("error");
        }
        this.isLoading = true;
        const { data } = await getArticleById(this.articleId);
        console.log(data);
        this.article = data.data;
        // 注意：数据更新后并不会同步更新页面，所以想要获取数据更新后的页面元素，需要延时处理
        setTimeout(() => {
          this.previewImg();
        });
      } catch (err) {
        // 加载失败404
        if (err.response && err.response.status === 404) {
          this.errStatus = 404;
        }
        this.$toast("获取失败");
      }

      // 加载完成
      this.isLoading = false;
    },

    // 预览图片
    previewImg() {
      const contentEl = this.$refs["article-content"];
      const allImg = contentEl.querySelectorAll("img");
      // 获取文章内容中所有的图片地址
      console.log(allImg);
      // 遍历所有img节点，注册点击事件
      const images = [];
      allImg.forEach((element, index) => {
        images.push(element.src);
        element.onclick = () => {
          ImagePreview({
            images,
            // 预览图片的起始位置，默认显示第几章
            startPosition: index,
            // 显示关闭按钮
            closeable: true,
            // 点击关闭,触发的回调函数
            onClose() {},
          });
        };
      });
    },

    // 发布评论监听的函数
    onPostSuccess(data) {
      // 关闭发布文章弹出框
      this.isPostShow = false;
      // 将发布内容显示到列表顶部
      this.commentList.unshift(data.new_obj);
    },

    // 回复评论
    onReplyClick(comment) {
      // 将子组件中传给我评论对象储存到当前组件
      this.currentComment = comment;
      this.isReplyShow = true;
    },
  },
};
</script>

<style scoped lang="less">
@import "./github-markdown.css";

.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
